The existence of men in the future becomes a matter of grace if it is true that sperm can one day be manufactured in laboratories. Women have been mildly assessing their men since last week's scientific breakthrough, weighing up the non-biological advantages of keeping them on.
It is less taxing to imagine a world without women, because there are more clues, starting with the Bible. There is not much psychological or emotional description from Adam about his bachelor days, which is what must have made them so pleasant for him. Genesis is like any male diary, a chronology of events with plenty of action and no self-analysis. Everything was dandy until Adam lost a rib and along came Eve. She immediately started lecturing him about the correct dose of vitamin C and introduced him to the joy of clothes.
Perhaps because men have a spiritual memory of their ancestral stag night, they find it surprisingly effortless to adapt to a world without women. It is like a Will Ferrell movie: awesome.
If you ask women what it would be like without men, they will respond with a minor fit of ecstasy about a future that demonstrates their exasperation with the present: no more clothes on the floor, no mud on the carpets, no Sky+. In sum, no more constant, small interruptions to life's quest for self-improvement.
If you ask men to envisage life without women, they may give a small, contented smirk. What they see is the status quo. A world of gadgets and sport and lager.
The visibility of women in public life is historically recent and can still look like an aberration. The corporate cleansing that takes place is a male corrective. The graduate intake for companies may be 50 per cent female, but it shrinks to 30 per cent at managerial level and not much more than 10 per cent at the top. Helen Alexander, head of the CBI, said after her appointment that there were commercial advantages to having some women in the mix. Imagine men having to plead the same case.
Without women, men revert to "group think". They share a worldview, similar interests, the same golf course. A world without women is one where men can finish each other's sentences. It is restfully monotone. That is why sentimentality towards women tends to be limited to the private sphere.
Men, and particularly boys, bereft of female tenderness is a popular theme in literature and brims with poignancy in real life. The pathos is keenly felt by women. I read Simon Carr's account of the film based on his book The Boys Are Back in Town with the emotional resolve of butter. The Independent writer brought up his two sons alone after his wife died of cancer in 1994 – their male bravado is touching and fragile.
He writes: "We lived among pizza boxes, videos, newspapers, takeaways, cartons, toys and machines. But to our minds, we were not slobs. We were too athletic, too active."
Boys can have all the fun in the world but still feel neglected. One of Carr's sons finally gives into grief when his father cuts his toast wrongly. Homeliness and order is created by patient attention to details. Motherhood is an endless observation of the small needs of others.
The comic pathos in the withdrawal of the maternal figure lies in the rough care of those left behind. The American writer Dave Eggers employs this orphan humour in his memoir about bringing up his eight-year-old brother Toph, A Heartbreaking Work of Staggering Genius: "There are times when I'm concerned about Toph's expression when I'm really singing, with vibrato and all, singing the guitar parts and everything, an expression that to the untrained eye might look like abject terror or revulsion – but I know well enough that it is awe."
A rougher justice is dealt out to the young would-be dancer Billy Elliot from a father who does not know how to combine paternal strength with maternal tenderness. His learnt appreciation of his son's sensitivity as well as his talent is a process of feminisation.
The most famous motherless boy of the moment is Harry Potter, whose strength and vulnerability derives from memories of his mother. The presence of women, even as ghosts, is a relatively recent concession, and it has changed the character of literature.
The critic Allan Bloom argued that feminism distorted our reading of the classical texts. In his seminal book The Closing of the American Mind, he wrote: "Literary criticism concentrated on the private, the intimate, the feelings, thoughts and relations of individuals, while reducing to the status of a literary convention of the past the fact that the heroes of many classic works were soldiers and statesmen engaged in ruling and faced with political problems."
Presumably Bloom would have despised the current feminisation of Trafalgar Square, where soldiers and statesmen must rub along with the private and intimate expressions of individuality being made on the fourth plinth.
Certainly, self-assertive women in the classics are not usually regarded as a positive thing. Medea, Clytemnestra and Phèdre were not contented women. Patience and loyalty are highly prized, but the women who are not weaving or sighing are usually trouble. Helen of Troy is a warning to all men to beware beautiful women seeking self-fulfilment.
A world without women is a world without discord.
When the Any Questions panel was asked about the effect of men being made redundant by bottled sperm, the former Tory chancellor Norman Lamont replied breezily that he supposed there would be no wars. Amazons apart, Boudicca excepted, women may not fight wars, but they are certainly capable of starting them. Elizabeth I may have been accused of caution by Sir Walter Raleigh, but she sent out her fleets, as did Margaret Thatcher. Hillary Clinton fought an election campaign on a refusal to blink and an ability to take a 3am call. It was her male opponent and future boss who spoke out against the Iraq war.
It is true that it is wives and mothers particularly who are on the rack over the terrible casualties in Afghanistan this week. The female quality of empathy makes the nightmares more ghastly. But it does not mean that women are appeasers. Aung San Suu Kyi has been steadfast. Women have played great parts in trying to change the destiny of Iran.
It is unusual to see the same recklessness in women as in men. The lunacy of the banks was mostly, although not exclusively, male-inspired.
There would be some cultural consequences to a world without women. I guess it would mean the end of the rom com, and that publishing would be carved up between Antony Beevor and Jeremy Clarkson. There would be no fiction published at all.
Television comedy is already a male preserve and, despite their polite encouragement , the majority of men would be happy to ditch female sports, except perhaps athletics.
I would be interested to see what happened to the "female economy". You would expect the beauty industry to collapse, but vanity is not in fact a female prerogative and there is nothing new in male narcissism.
I would predict a disastrous decline in fabric shops and a vast monopoly of Homebase. There might or might not be an increase in cars. Would men, free of sapping women, return to their first love of Hummers, or would they be content to remain as warrior cyclists? Could Boris, liberated from the female vote, allow unfettered tall buildings to compete across London? Perhaps men can build new bridges to link them all.
Now that collaboration and consultation can go out of the window, men can reinstate big-swinging-dick offices with enormous desks. They can ditch the family portraits in favour of fantasy glamour models; they can pad around in their old socks and do up their shirts with safety pins. They can watch the Moon landings on a loop on their kilometre-wide plasma TVs. They can start whistling again.
A world without women may seem to men a matter of relief. What they will lose is variety. Even the most fanatical of Garrick Club members must occasionally wish for a different opinion, another kind of laugh, a missing scent. The G8 summit was what men love best, a forum of tremendous importance and dignity. Yet a newspaper photograph showed both President Obama and President Sarkozy momentarily distracted by a silky female backside.
The FT's Lucy Kellaway wrote modestly last week of her new role as a non-exec. She said that the presence of women perked things up a bit. A world without women would be as unexciting as a world without men.
Sarah Sands is deputy editor of the London Evening Standard